The circumpolar Subantarctic Zone (SAZ) is a globally significant region of water mass formation and carbon dioxide uptake from the atmosphere. Here we synthesise the results of nine voyages over 8 years to describe the seasonal variation in mixed layer properties in the SAZ south of Australia for comparison with biogeochemical process studies carried out in late summer (March 1998) as part of the SAZ Project. Winter mixing extends to depths greater than 400 m, resulting in the formation of Subantarctic Mode Water. In summer the mixed layer shoals to 75-100 m, depths which are still sufficiently deep that phytoplankton growth may be light limited. Nitrate and phosphate concentrations are reduced in summer( e.g., nitrate decreases from greater than 15 to less than 5/ micro mol kg- 1) but remain well above limiting levels. Silicate in contrast, is low throughout the year (4/micro mol kg- 1 in winter and less than 2 / micro mol kg- 1 in summer). Water mass properties along a north-south hydrographic section in March 1998 suggest that near-surface waters spread from south to north across the Subantarctic Front (SAF), supplying cool, fresh, nutrient-rich water to the SAZ. As a consequence, the properties of the southern SAZ differ from those farther north: the mixed layer in the south is cooler, fresher, deeper, higher in nutrients, and bounded below by a halocline (rather than by a seasonal thermocline, as in the northern SAZ). The contrast between the northern and southern SAZ persists throughout the year, suggesting the cross-front exchange occurs year-round and likely contributes to the differences in seasonal thermal amplitude and algal biomass accumulation seen in satellite images. Density-compensated horizontal gradients of temperature and salinity are common in the mixed layer of the SAZ and the northern SAF, consistent with the hypothesis that the vigour of lateral mixing in the mixed layer is a strong function of the magnitude of the lateral density gradient. CTD Data are available for access via the provided URL. Data from the following voyages of the Aurora Australis were used: 1991-1992 Voyage 1 1992-1993 Voyage 9 1994-1995 Voyage 4 1994-1995 Voyage 7 1995-1996 Voyage 1 1996-1997 Voyage 1 1997-1998 Voyage 6

This is a scanned copy of the annual report on the scientific work undertaken at Davis Station in 1985. The report was written by J.B. Gallagher. Paraphrased from the introduction: This report describes the work undertaken at Davis from January 1985 to November 1985. Aims of the program: 1) Description of the seasonal circulation patterns within Ellis Fjord. This was done by measuring the salinity temperature profiles at selected stations down the length of the fjord, its entrance and the sea. 2) Origin, age, circulation and mixing rates of the meromictic basin. The deep waters of the meromictic basin have a salinity of approximately 1.4 the salinity of sea water. It's possible that this may be due to old sea water left behind after an isostatic uplift with subsequent concentration through evaporation. Calculation of mixing rates and description of the water circulation will explain why the basin is so stable. 3) Recent sedimentation rates within the meromictic basin. Sediment was collected from 110m for 137Cs analysis - the peak in the profile should indicate the age of that layer of sediment as 1963, during which atmospheric bomb tests released large quantities of 137Cs into the atmosphere. 4) Biogeochemistry of sulphur, iron, manganese, aluminium and carbon within the meromictic basin. The deep waters of the meromictic basin are anoxic (from 45m). This gave an ideal opportunity to study the cycling of the above redox active elements. 5) Collection and processing of water for trace element analysis and organometallics.

We report on the late winter oceanography observed beneath Antarctic sea ice offshore from the Sabrina and BANZARE coast of Wilkes Land, East Antarctica (115- 125 E) in September-October 2007 during the Sea Ice Physics and Ecosystem eXperiment (SIPEX) research voyage. A pilot program using specifically designed 'through-ice' Conductivity-Temperature-Depth (CTD) and acoustic Doppler current profiling (ADCP) systems was conducted to opportunistically measure water mass properties and ocean currents during major ice stations. This project involved two independent sub-ice observation platforms: A winch-driven Conductivity-Temperature-Depth system for measuring basic water mass properties and an acoustic Doppler current profiling (ADCP)/GPS system for measuring ocean currents and ice drift. Hereafter these are referred to as the CTD and ADCP systems respectively. The CTD system comprised of an Falmouth Scientific Institute (FSI) CTD instrument, a tripod and over 1000m of polyethylene rope on a winch/drum attached to a metal sled.